This invention relates to a method of controlling reception of data which is stored, e.g., in a receive buffer of a page printer and on occasion reread.
In conventional printers which receive and print out the data sent in, a receive buffer is provided to receive a large amount of the data at one time, because the printing speed is slow. The data stored in the receive buffer is read out at a speed commensurate with the printing speed. Accordingly, a method of controlling the reception of data has been adopted wherein a write pointer which shows the address at which the data is written into the receive buffer, and a read pointer which shows the address from which the data is read out, are established.
As with dot impact printers which are not required to conduct processing after printing, the operation is completed after merely one readout of the data for printing. However, with page printers such as laser printers, liquid crystal printers, or LED printers, there is the necessity, subsequent to printing, for after-processing such as fixing. Also there are occasions upon which, owing to a paper jam at this stage, the printed page is rendered unusable in which case the same contents must be printed once again. However, in the method of controlling the reception of data which utilizes the aforementioned write pointer and read pointer, the data which has been once read out by the read pointer is erased as the processing has been completed, thereupon liberating the area of data as a write area. Thus it is difficult to print the same data a second time.
A recording apparatus which is capable of printing the same contents a second time, described in U.S. Pat. No. 4,571,069. However, this recording apparatus needs a plurality of receive buffers, and the changeover between the writing-in and reading-out of data is accomplished by means of a switch, thereby making for inefficient utilization of the receive buffers.
The present invention solves the aforementioned problems, and provides a method of controlling the reception of data with which it is possible to read the data out a second time. The invention is furthermore capable of improving the utilization efficiency of the receive buffer that stores the received data.